Direct Rate Measurements of the Combination and Disporportionation of Vinyl Radicals

Article abstract of DOI:10.1021/j100365a040

The rates of removal of vinyl radicals (C2H3) by means of combination and disproportionation reactions have been directly measured at room temperature.Vacuum-ultraviolet (vacuum-UV) flash photolysis of divinylmercury was used to generate vinyl radicals, and vacuum-UV absorption kinetic spectroscopy was used to monitor the time history of vinyl radicals through their absorption at 1647.1 Angstroem.The absolute rate constant for vinyl radical decay was determined to be 1.0E-10 cm³molecule^-1s^-1.A ratio of 4.7 for the combination/disproportionation rate constantswas measured by gas chromathographic analysis of the final reaction products.Absorption coefficients for the vinyl radical absorption in the 1650-Angstroem region were determined.The absolute rate constants for combination and disproportionation are then 8.2E-11 and 1.8E-11 cm³molecule^-1s^-1, respectively.